#include "core/message.h"
#include <iostream>
#include <cstring>

namespace biz {
	// CRC 高位字节值表
	static const uint8_t auchCRCHi[] = {0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, //
	                                    0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, //
	                                    0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, //
	                                    0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, //
	                                    0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, //
	                                    0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, //
	                                    0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, //
	                                    0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, //
	                                    0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, //
	                                    0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, //
	                                    0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, //
	                                    0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, //
	                                    0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, //
	                                    0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, //
	                                    0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, //
	                                    0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40};

	// CRC 低位字节值表
	static const uint8_t auchCRCLo[] = {0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, //
	                                    0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 0x08, 0xC8, //
	                                    0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, //
	                                    0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3, 0x11, 0xD1, 0xD0, 0x10, //
	                                    0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4, //
	                                    0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A, 0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, //
	                                    0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, //
	                                    0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26, 0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, //
	                                    0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, //
	                                    0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, //
	                                    0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, //
	                                    0xB4, 0x74, 0x75, 0xB5, 0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, //
	                                    0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, //
	                                    0x9C, 0x5C, 0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, //
	                                    0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C, //
	                                    0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 0x40};

	uint16_t CRC16(const char *ptr, int len) {
		uint8_t uIndex;
		uint8_t crcH = 0xFF; // H CRC 字节
		uint8_t crcL = 0xFF; // L CRC 字节
		while (len--) {
			uIndex = crcH ^ *ptr++; // 计算CRC
			crcH   = crcL ^ auchCRCHi[uIndex];
			crcL   = auchCRCLo[uIndex];
		}
		return ((crcH << 8) | crcL);
	}


	size_t message_size(const Message &msg) {
		size_t size = sizeof(msg.magic);
		size += sizeof(msg.flag);
		size += sizeof(msg.routers);
		size += sizeof(msg.payload_len);
		size += msg.payload_len;
		size += sizeof(uint16_t); // CRC16
		return size;
	}

	void serialize(const Message *msg, char *buffer, const size_t len) {
		if (len < message_size(*msg)) {
			cout << "[serialize] message_size error." << endl;
			return;
		}

		size_t offset = 0;
		// memset(buffer, 0, len);
		memcpy(buffer, &msg->magic, sizeof(msg->magic));
		offset += sizeof(msg->magic);

		memcpy(buffer + offset, &msg->flag, sizeof(msg->flag));
		offset += sizeof(msg->flag);

		memcpy(buffer + offset, &msg->routers, sizeof(msg->routers));
		offset += sizeof(msg->routers);

		memcpy(buffer + offset, &msg->payload_len, sizeof(msg->payload_len));
		offset += sizeof(msg->payload_len);

		if (msg->payload_len > 0 && msg->payload_data != nullptr) {
			memcpy(buffer + offset, msg->payload_data, msg->payload_len);
			offset += msg->payload_len;
		}

		// 校验和
		uint16_t checksum = CRC16(buffer, offset);
		memcpy(buffer + offset, &checksum, sizeof(checksum));
	}

	void deserialize(Message *msg, const char *buffer, size_t len) {
		if (len < (sizeof(msg->magic) + sizeof(msg->payload_len) + sizeof(uint16_t))) {
			cout << "[deserialize] message_size error." << endl;
			return;
		}

		size_t offset = 0;
		memcpy(&msg->magic, buffer + offset, sizeof(msg->magic));
		offset += sizeof(msg->magic);

		memcpy(&msg->flag, buffer + offset, sizeof(msg->flag));
		offset += sizeof(msg->flag);

		memcpy(&msg->routers, buffer + offset, sizeof(msg->routers));
		offset += sizeof(msg->routers);

		memcpy(&msg->payload_len, buffer + offset, sizeof(msg->payload_len));
		offset += sizeof(msg->payload_len);

		if (msg->payload_len > 0) {
			msg->payload_data = (char *) malloc(msg->payload_len);
			if (msg->payload_data == nullptr) {
				perror("failed to alloc memory for paload_data.");
				return;
			}
			memset(msg->payload_data, 0, msg->payload_len);
			memcpy(msg->payload_data, buffer + offset, msg->payload_len);
			offset += msg->payload_len;
		}

		uint16_t checksum;
		memcpy(&checksum, buffer + offset, sizeof(checksum));

		uint16_t check = CRC16(buffer, offset);
		if (check != checksum) {
			cout << "CRC16 checksum error." << endl;
		}
	}

	void free_message(Message *msg) {
		if (msg && msg->payload_data) {
			free(msg->payload_data);
			msg->payload_data = NULL;
		}
	}
} // namespace biz
